there is a very helpful and in-depth article on this subject on the web. i don't have the link that will take you directly to it. but if you type in your search engine "What do publishers do?" it will take you to a list, as you are aware, choose the one that is an excerpt from the book "Getting it Published" by William Germano. there is an overview of the publishing industry and how the industry functions. an editor's responsibilities, different types of editors and what they do, publishers' responsibilites, agents and authors. i found it insightful and hope the excerpt will benefit you as well and answer your question. sorry i couldn't be of more help.
~us
